\\[-1.8ex] Soil Heterogeneity & $-$0.057$^{**}$ & $-$0.056$^{**}$ & $-$0.057$^{**}$ & $-$0.057$^{**}$ & $-$0.057$^{**}$ & $-$0.057$^{**}$ & $-$0.057$^{**}$ \\ 
  & (0.024) & (0.024) & (0.024) & (0.024) & (0.024) & (0.024) & (0.024) \\ 
\\[-1.8ex] 
Observations & 14,169 & 14,169 & 14,169 & 14,169 & 14,169 & 14,169 & 14,169 \\ 
R$^{2}$ & 0.817 & 0.817 & 0.817 & 0.817 & 0.817 & 0.817 & 0.817 \\ 
